catalyst
by astarisms
Summary: "I love the way her breathing changes as soon as I touch her body."


There is a lot about Natalie McAllister that Lucifer can admit he finds endearing, though he would only ever admit it to himself and only when he'd run out of topics to occupy his mind long enough to keep it from drifting back to her.

(Inevitably, it always did.)

It's the most frustrating, mind-numbing thing, to try and pick apart how his affection for her works. What used to be the qualities that drove him half to insanity had somehow become the ones that made his chest ache in some foreign, long forgotten way.

Her incessant smiling, her too-loud laughter, her naive desire to see the good in everyone, even those who didn't deserve it, used to drive him up a wall. Now, he feels as if he would turn the world upside down to make sure she never lost that light that burned so brightly in her.

(To make sure she never became like _him_.)

And there are other things, too. Things that he's learned about her over time that makes his heart beat a painful rhythm against his ribcage.

She can sing — and not the loud, eardrum shattering, nails-on-chalkboard sounds she usually makes. She sings quietly and quite well in the shower, or on rainy days when she thinks he isn't around.

(He loves her real voice.)

She has a natural ability for bringing anyone out of a sour mood — another quality he'd originally hated, but now appreciates. He had never realized how exhausting his unwavering rage was until she had shown him otherwise, and it was like breathing again.

(He doesn't need air, but even if he did he thought she might be enough.)

Her eyes light up when she's happy or excited — no, they don't glow like his, but they might as well for how bright the green becomes. She doesn't glow in the literal sense, but the change is just as visible to the naked eye.

(He notices it a lot when she's with him, and it knocks the nonexistent breath out of him.)

She's always so forceful in everything she does, too passionate to slow down, too excited to think twice — except sometimes, when she touches him. Not always, just in the moments it matters. She twines their fingers with a touch so light it might've been nonexistent and she strokes his hair back from his forehead with the pressure of a feather.

(He always shudders when she touches him like this, so unused to this kind of gentleness.)

But best of all, she's an open book — all of her emotions play out clearly across her face and she wears her heart on her sleeve. He used to think it was dangerous, for her, to be so transparent around him. Now, he still thinks it's dangerous, but not for her.

(It drives him crazy how she doesn't even try to hide how her breathing changes as soon as he touches her.)

She never tries to hide from him how much she wants him, how much she aches for his touch and it makes his head spin. She covers his hands with hers and guides them beneath the hem of her shirt until he takes the hint and pushes it up, up, up, and as soon as her hair is settling around her again she's reaching for him.

She grabs his face and kisses him, and there's no need to be gentle in this moment so she's not. He can hear how her heart races, her blood rushing through her veins with the full force of her passion, and _oh,_ he loves how she burns for him.

He breaks away from her lips to trail kisses down her neck and lets her pull him down over her. She twists her fingers into his hair and she moans, her breaths quickening at the onslaught of his teeth and his tongue against the pulse in her throat.

"Lucifer," she squirms as he shifts lower and lower still. His fangs tug the skin of her breast just above the line of her bra and her back arches, catching her gasp against the back of her teeth and swallowing it back down.

It's music to his ears. As much as he loves her singing, this is better.

He tries to go further, reaching underneath her to undo the clasp at her back as he continues to kiss down her stomach. Her hand is still in his hair, though, and she tugs hard enough to catch his attention.

She shakes her head and everything that she wants is spelled out in the light of her eyes and at one point, he was a stronger man, but he's not anymore. Of all the things he's immune to, that look is not one of them.

Who is he to refuse her?

He climbs back up her body, tearing her bra away from her chest. In his ascent, he flicks his tongue against one rosy nipple and she reels, seizing his head and pulling him back to her lips so hard their teeth clash.

His body hardens, humming in response to the effect he has on her as he eases back just enough to tease his tongue into her mouth. He groans, low and guttural, at the taste of her and Natalie rocks her body against his in response with a whine.

He forces her hips down against the mattress and fumbles for the button of her jeans. She laughs into their kiss and slips her hands between them to help him. He pulls them off of her as quickly as they'll come, along with her panties.

Her fingers are already occupied with getting the knot in his toga undone and he leaves her to it, his eyes sweeping over her body. His lets his hands glide down her sides and listens as her breath hitches, watches as her chest heaves quickly once or twice. His eyes darken and his hand trails farther, under the curve of her ass and beneath her thigh, lifting it like he's going to wrap it around him then pushing it to the side.

Natalie looks up from her task, surprised, but before she can even open her mouth he's slipping a finger inside of her, his thumb finding her clit and rubbing deep circles around it. Her jaw drops and her hips cant to the rhythm his fingers set, squeezing her eyes shut and moaning loudly.

She drops her hands from his toga and grabs his wrist, not so much guiding his hand as making sure he doesn't remove it. His eyes scorch her skin with their intensity as he watches her and adds another finger to the one pressing in and out of her, and she chokes.

She's so _ready._ She's warm and wet and the way she squeezes around his fingers makes it hard to focus.

He pulls his hand away from her and she cries out in protest, but he leans forward to kiss her to make up for it as he yanks at the knot around his waist and lets the shredded fabric pool in the floor.

Natalie clutches at the back of his neck so tightly it might have hurt if he was human. But he's not, and instead she's a good anchor for when he finally pushes into her, both of them shuddering at the immediate gratification of being entwined so completely.

Now, he really does guide her legs around his waist and she digs her heels into the dimples of his lower back as he begins to thrust. She quivers beneath him, surrendering to the pleasure of him.

She breathes his name like a prayer, reverent and filled with emotion, though what she's feeling now and who she's feeling it with is far from holy. He dips his head to the hollow above her collarbone and thinks, wrapped up in her body and drowning in her ecstasy, that he could spend a lifetime worshipping her.

And, in true Natalie fashion, when her orgasm finally hits her, she lets it consume her. She throws her head back and she arches off the mattress and and cries out his name in broken rapture, and he worries if not for the weight of his body pressing her back down that she'd surely float away.

He finds his own release moments later, as she's still wrapped tight around him and clinging to him like he's her only link to reality. He growls against her throat and it sends a thrill through her. She shivers and clutches him closer.

She sighs contentedly when he rolls off of her, curling around him like he's a housecat instead of the fallen angel who could crush her skull in seconds. He wraps his arm around her as well, pulling her into his chest.

She loops her leg around his thigh, keeping him pressed close and tucks her head beneath his chin. He had learned quickly enough after the first time that Natalie liked to cuddle afterwards, though he shouldn't have been surprised.

Though he would never admit it out loud, he likes how she curls up against him, naked and open and completely vulnerable. She doesn't seem to mind, this slip of a girl who trusts first and asks questions later.

(She reminds him that he's not the monster he's always thought he was.)


End file.
